A bytecode interpreter for the Lox language from Crafting Interpreters implemented in Zig.
Building zig-lox requires Zig 0.10. Zig binaries are available through several package managers, or from zig's download page.
REPL:
zig run src/main.zig
Executing a file:
zig run src/main.zig -- examples/arithmetic.lox
To run tests, run
make test
This runs the tests from the book using a test harness written in Zig. Note that test/for/closure_in_body.lox is currently skipped because closuring the induction variable of a loop works differently in zig-lox than in clox.
Running make creates a debug build of zig-lox at bin/lox.
To create a release build, run make release.
zig-lox can be compiled to a freestanding Web Assembly (WASM) library to run in a web browser or in node. Running
make wasm
will create a build at build/wasm-lib.wasm. An example of using the WASM library through node is provided in js/main.js. Similarly to the lox binary, this provides a REPL through
node js/main.js
and can execute a specified lox source file, for example:
node js/main.js examples/arithmetic.lox
A simple web REPL powered by the WASM library is available in the www directory. Try it live.
To run the web REPL locally, run
make www-server
(note, requires Python 3 to be available), and visit localhost:8000.
It is also possible to produce a build targeting the WebAssembly System Interface. Running
make wasi
will create a build at build/lox-repl.wasm, which can be run using Wasmer like this:
wasmer run build/lox-repl.wasm
So far, only the REPL is supported in the WASI build--executing a source file is not yet possible.
This Lox REPL is also available as the wapm package jwmerrill/lox-repl. You can try it online at webassembly.sh by installing it
wapm install jwmerrill/lox-repl
and then running
lox-repl
Note: right now this only seems to work well in Chrome.
Complete.
Crafting Interpreters source code
I've taken a lot of inspiration from zox, an earlier Zig implementation.